CR – Polychloroprene (Neoprene)
Chloroprene Rubber (CR), also known as chlorobutadiene rubber, is an important diene-based elastomer. The name Neoprene® is a registered trademark of DuPont Performance Elastomers.
The commercial grades are mostly trans-1,4-polychloroprene produced by free-radical emulsion polymerization of 2-chloro-1,3-butadiene. The chlorine in the polymer reduces the reactivity to many oxidizing agents.
Chloroprene rubber typically displays good resistance to ozone
cracking, heat aging and to chemical attack. For example, it has
good resistance to many chlorofluorocarbons, aliphatic hydrocarbons,
mineral oils, greases and ozone, but only moderate or poor resistance to
acids, solvents, and fuels. Its flame resistance is excellent. In
fact, chloroprene is one of the few rubbers that are
self-extinguishing. It also gives excellent rubber-to-metal bonds.
However, chloroprene tends to harden over time and degrades in the
presence of some fairly common chemicals such as hydrochloric acid,
acetone, xylene, acetic acid, and hydrogen peroxide.
Its mechanical properties are generally inferior to those of natural rubber but it has superior chemical resistance.
COMMERCIAL CR ELASTOMERS
Major manufacturers of polychloroprene elastomers are Lanxess, Tosoh, and Denka.
Chloroprene is used primarily for gaskets, cable jackets,
tubing, seals, O-rings, tire-sidewalls, gasoline hoses and
weather-resistant products such as wet suits and orthopedic braces.
It is also used as a base resin in adhesives, electrical
insulations and coatings.
It has many useful properties and a reasonable price.
Its typical working temperature range is between -35°C and +100°C.